HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Berg, R. K. Articles by Lieberman, M. T. Search for Related Content PubMed Articles by Berg, R. K., Jr. Articles by Lieberman, M. T. Agricola Articles by Berg, R. K. Articles by Lieberman, M. T.

Nodule Occupancy by Introduced Bradyrhizobium japonicum in Iowa Soils

Forage and Range Res. Lab., Utah State Univ., Logan, UT 84322-6300
Dep. of Agronomy, Iowa State Univ., Ames, IA 50011
Allelix, Inc., 6850 Goreway Dr., Mississauga, Ontario, Canada L4V 1P1
Hunter Biosciences, Inc., 3208 Spnng Forest Rd., Raleigh, NC 27604

^* Corresponding author.

Competitive indigenous strains of Bradyrhizobium japonicum occupy many soils of the Midwest, but they are generally considered to be less efficient in fixing N₂ than many strains added as inoculants. Inoculant strains will not improve _N2 fixation in soybean [Glycine max (L.) Merr.], however, unless they are able to form nodules on the host plant. This research evaluated whether strains selected for competitiveness in the greenhouse could compete against indigenous bradyrhizobia in the field in forming nodules when added at rates used for commercial inoculants, and whether higher nodule occupancy resulted in improved plant growth. Plots were established in north-central Iowa at seven sites on four representative soil series. Seven to 12 strains were introduced in two or three soils each year from 1983 to 1985 at approximately 5.8 log₁₀ viable cells per centimeter of row as granular-peat inoculants. Results showed that average strain recoveries ranged from 0 to 46%. Some introduced strains differed in their competitive ability among the sites tested. The most competitive strains were AN8, AN10, AN11, AN23, AN27, and AN30, which typically occupied at least 20% of the nodules at a given site. When considering all members of each serogroup tested, strains from serogroup 123 were the best competitors. Increased nodule occupancy by the introduced strains did not result in increased plant growth or yield. Nodulating and nonnodulating ‘Clark’ isolines and urea fertilizer treatments were used to evaluate contributions from N₂ fixation and plant growth with added N fertilizer.

Received for publication May 18, 1987.

This article has been cited by other articles:

				R. M. Zablotowicz and K. N. Reddy Impact of Glyphosate on the Bradyrhizobium japonicum Symbiosis with Glyphosate-Resistant Transgenic Soybean: A Minireview J. Environ. Qual., May 1, 2004; 33(3): 825 - 831. [Abstract] [Full Text] [PDF]